In many portable electronic devices, such as mobile communication devices, displays present information to a user. For example, polymer-dispersed liquid crystal (PDLC) display technology can display video and text information and, utilizing twisted nematic (TN) polymer segments, can also provide an optical shutter operation. Optical shuttering is sometimes used to present information to a user and is particularly adapted to touchscreen operation where the information represents control icons (e.g., forward, reverse, pause, and play control symbols for video operation). TN/PDLC displays typically include an electroluminescent (EL) backlight for operation in both high and low ambient light conditions.
While providing modular optical shuttering operation by selectively driving the TN segment electrodes, operation of the EL backlight and selective driving of the TN segment electrodes disadvantageously creates an electrically noisy environment for sensing touchscreen inputs, thereby hampering touchscreen operation. Conventionally, an indium-tin oxide (ITO) ground plane is provided below the TN segment electrodes and above the EL backlight to control the electrical noise and improve the touchscreen operation. However, addition of the ITO ground plane increases the thickness of the display and the cost and complexity of the display manufacture. In addition, the ITO ground plane connection is susceptible to failure, thereby reducing display yield and/or increasing field failure defects. Also, the ITO ground plane is not fully transmissive, thereby reducing the brightness and effectiveness of the EL backlight.
Thus, there is an opportunity to eliminate an ITO ground plane from a TN/PDLC touchscreen. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the disclosure.